Midline interhemispheric lesion: question

Abstract

Pericallosal lipomas are rare, occurring in 1 in 2,500 to 25,000 autopsies [1]. The lesion is closely related to the corpus callosum in the interhemispheric fissure and often associated with callosal dysgenesis or agenesis [1]. They are classified as tubulonodular or curvilinear, the former being more common [2]. Tubulonodular pericallosal lipomas are located anteriorly, rounded and generally >2 cm thick. They are associated with significant callosal dysgenesis and fronto-facial anomalies. The less common curvilinear pericallosal lipoma are posteriorly located, thin (<1 cm) and curve around the corpus callosum [2,3]. Pericallosal lipomas are believed to result from an abnormal persistence and differentiation of the meninx primitive [4]. This